494 research outputs found
Psychometric properties of Persian version of the multifactor leadership questionnaire (MLQ)
Background: Outstanding leadership is one of the important and vital concepts in management and educational leadership debates especially in educational organizations such as universities. Thus, effective educational leadership and adopting an appropriate tool to assess leadership in education are crucial in these institutions. The present study was conducted to develop an instrument for measuring the leadership style in faculty members. Methods: In this descriptive cross-sectional study, content and face validity of Multifactor Leadership Questionnaire (MLQ) was examined using the opinions of 10 experienced faculty members as a panel of experts. For construct validity, 210 questionnaires were administered to faculty members of Tehran University of Medical Sciences. Confirmatory factor analysis was run using principal component analysis and Varimax rotation method. The reliability of the scale was measured through internal consistency using Cronbach's alpha formula. Confirmatory factor analysis was used to examine the construct validity of the questionnaire. Data were analyzed using SPSS v.16 and LISREL software. Results: Factor analysis and expert opinion resulted in a questionnaire with 18 items across six subscales including idealized influence, inspirational motivation, intellectual stimulation, individualized consideration, contingent reward, and management by exception. The reliability coefficient of the questionnaire was acceptable (0.90). Confirmatory factor analysis showed that the scale had appropriate goodness of fit. Conclusion: The 18-item Educational Leadership Questionnaire was found to have acceptable validity and reliability for measuring leadership style in the faculty. It is recommended that the questionnaire be administered to a larger sample
Date-Driven Approach for Identifying State of Hemodialysis Fistulas: Entropy-Complexity and Formal Concept Analysis
The paper explores mathematical methods that differentiate regular and
chaotic time series, specifically for identifying pathological fistulas. It
proposes a noise-resistant method for classifying responding rows of normally
and pathologically functioning fistulas. This approach is grounded in the
hypothesis that laminar blood flow signifies normal function, while turbulent
flow indicates pathology. The study explores two distinct methods for
distinguishing chaotic from regular time series. The first method involves
mapping the time series onto the entropy-complexity plane and subsequently
comparing it to established clusters. The second method, introduced by the
authors, constructs a concepts-objects graph using formal concept analysis.
Both of these methods exhibit high efficiency in determining the state of the
fistula.Comment: Accepted in AIST-2023 conference. Yerevan, Armeni
The McCusker subjective cognitive impairment inventory (McSCI): A novel measure of perceived cognitive decline
Background: Subjective cognitive decline (SCD), i.e. self/other-reported concerns on one’s cognitive functioning without objective evidence of significant decline, is an indicator of dementia risk. There is little consensus on reliability and validity of the available SCD measures. Therefore, introducing a novel and psychometrically sound measure of SCD is timely. Objective: The psychometric properties of a new SCD measure, the McCusker Subjective Cognitive Impairment Inventory–Self-Report (McSCI-S), are reported. Methods: Through review of previously published measures as well as our clinical and research data on people with SCD, we developed a 46-item self-report questionnaire to assess concerns on six cognitive domains, namely, memory, language, orientation, attention and concentration, visuoconstruction abilities and executive function. The McSCI-S was examined in a cohort of 526 participants using factor analysis, item response theory analysis and receiver operating characteristic (ROC) curve. Results: A unidimensional model provided acceptable fit (CFI = 0.94, TLI = 0.94, RMSEA [90% CI] = 0.052 [.049, 0.055], WRMR = 1.45). The McSCI-S internal consistency was excellent (.96). A cut-off score of ≥24 is proposed to identify participants with SCDs. Higher McSCI-S scores were associated with poorer general cognition, episodic verbal memory, executive function and greater memory complaints and depressive scores (P \u3c.001), controlling for age, sex and education. Conclusions: Excellent reliability and construct validity suggest the McSCI-S estimates SCDs with acceptable accuracy while capturing self-reported concerns for various cognitive domains. The psychometric analysis indicated that this measure can be used in cohort studies as well as on individual, clinical settings to assess SCDs
An investigation on the fatigue behavior of additively manufactured laser shock peened AlSi7Mg alloy surfaces
In the recent years, laser powder bed fusion of aluminum alloys has attracted extensive attention due to their
capacious application in the biomedical, aerospace, and other industrial sectors. This is due to the combined
capabilities of the laser powder bed fusion process and aluminum alloys bringing about complex shapes with
high performance associated with light-weight design. Despite their high potential, parts produced by laser
powder bed fusion suffer from residual stresses, surface irregularities and sub-surface defects limiting their full
exploitation in fatigue sensitive applications. Consequently, post-processing methods such as laser shock peening
can be employed to countermeasure these short-comings. This article reports on the effect of laser shock peening
on the fatigue life of AlSi7Mg alloy fabricated via laser powder bed fusion. Laser shock peening induced a
substantial improvement (around 50%) in the fatigue life when compared to the as-built parts. The improvements
were attributed to the closure of surface and sub-surface pores, re-entrant surface features and in
particular, induced compressive residual stress profile. The effects of laser shock peening were investigated
through systematic multi-scale analysis through destructive and non-destructive methods. Furthermore, a simple
fracture mechanics model was utilized to elucidate the effect of induced compressive residual stresses as the
principal actor in the corresponding fatigue life improvement
The effect of magnesium on bioactivity, rheology and biology behaviors of injectable bioactive glass-gelatin-3-glycidyloxypropyl trimethoxysilane nanocomposite-paste for small bone defects repair
Injectable bioactive glass-based pastes represent promising biomaterials to fill small bone defects thus improving and speed up the self-healing process. Accordingly, injectable nanocomposite pastes based on bioactive glass-gelatin-3-glycidyloxypropyl trimethoxysilane (GPTMS) were here synthesized via two different glasses 64SiO2. 27CaO. 4MgO. 5P2O5 (mol.%) and 64SiO2.31CaO. 5P2O5 (mol.%). In particular, the effects of MgO on bioactivity, rheology, injectability, disintegration resistance, compressive strength and cellular behaviors were investigated. The results showed that the disintegration resistance and compressive strength of the composite were improved by the replacement of MgO; thus, leading to an increase in the amount of storage modulus (G′) from 26800 to 43400 Pa, equal to an increase in the viscosity of the paste from 136 × 103 to 219 × 103 Pa s. Since the release rate of ions became more controllable, the formation of calcite was decreased after immersion of the Mg bearing samples in the SBF solution. Specimens’ cytocompatibility was firstly verified towards human osteoblasts by metabolic assay as well as visually confirmed by the fluorescent live/dead staining; finally, the ability of human fibroblasts to penetrate within the pores of 3D composites was verified by a migration assay simulating the devices repopulation upon injection in the injured site
The effect of LINC01296 expression in patients with cancer: A systematic review and meta-analysis
Background: Recently has been suggested that LINC01296 has an important role in tumor-promoting in different malignancies. We performed first meta-analysis to assess the association between the LINC01296 expression and clinicopathological criteria and the survival of patients with cancers. Methods: Relevant articles Identified by PubMed, EMBASE, Web of Science, and Scopus searching between December 2000 and 28 December 2018. Binomial data were evaluated by the odds ratio (OR) as the rapid statistic. The association between overall survival (OS) and the LINC01296 expression was evaluated using pooling the hazard ratio (HR) with its corresponding 95 confidence interval (CI). Results: Finally, 9 studies with 720 patients with cancer were included. The expression of LINC01296 showed a significant positive association with TNM stage (OR = 2.67, 95 CI = 1.83-3.88), tumor stage (OR= 2.22, 95 CI= 1.34-3.66) and lymph node metastasis (OR = 3.07, 95 CI = 2.23-4.21). A shorter OS was significantly associated with the expression of LINC01296 (HR = 3.95, 95 CI = 2.65-5.25) and lymph node metastasis (HR = 2.39, 95 CI =1.16-3.63). The OS did not show significant association with gender (HR = 0.83, 95 CI =-0.63-2.30) and tumor stage (HR= 2.66, 95 CI=-0.22-5.54). Conclusion: In conclusion, the results of this meta-analysis suggest that the expression of LINC01296 might be considered as a potential biomarker in patients with cancer. © 2020 Asian Pacific Organization for Cancer Prevention
Different effects of aerobic exercise and diaphragmatic breathing on lower esophageal sphincter pressure and quality of life in patients with reflux: A comparative study
BACKGROUND Gastroesophageal reflux disease (GERD) is a worldwide disorder with an increasing prevalence. The quality of life (QOL) of the patients may be influenced by reflux disease. Diaphragmatic breathing (DB), as well as aerobic exercise (AE), may improve the symptoms of reflux disease, although it remains a controversial issue. The aim of this study was to compare the effects of AE and DB on QOL and lower esophageal sphincter (LES) pressure of patients with moderate to severe reflux. METHODS This was a case-control study that was conducted for 8 weeks among patients with moderate to severe GERD. The block randomization method was designed to randomize patients into three groups (AE, DB, and control) to achieve equal sample sizes. The control group received omeprazole 20 mg once daily. The other groups, in addition to omeprazole, received AE and DB. QOL and LES pressure were measured before and after the study by Questionary and Manometry method, respectively. RESULTS 75 patients were enrolled in this study. Positive effects of DB on LES pressure was approved (p = 0.001). DB had significantly more effects on QOL than aerobic exercise (p = 0.003). AE can significantly improve QOL in patients (p = 0.02) but no significant change in LES pressure (p = 0.38). There was no change in the control group for both variables. CONCLUSION AE had no effects on LES pressure but can improve QOL of the patients. DB had more effects on QOL than AE, so injured or disable patients with reflux who cannot do AE, can benefit from DB to improve their reflux symptoms. © 2021 The Author(s)
Mdscs in Infectious diseases: regulation, roles, and readjustment
Many pathogens, ranging from viruses to multicellular parasites, promote expansion of MDSCs, which are myeloid cells that exhibit immunosuppressive features. The roles of MDSCs in infection depend on the class and virulence mechanisms of the pathogen, the stage of the disease, and the pathology associated with the infection. This work compiles evidence supported by functional assays on the roles of different subsets of MDSCs in acute and chronic infections, including pathogen-associated malignancies, and discusses strategies to modulate MDSC dynamics to benefit the host
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